How to repair odometer gear???

[351c4v71]

My odometer gear was crooked so the odometer wouldn't work, the gear kept skipping.
I tried to straighten it up and it broke off, of course. See picture, i red circle, the part that is broken off, it needs to be where red circle shows. So I drilled a hole through the broken off part and intended on attaching it to the main shaft by drilling a hole in the main shaft and sticking a small metal rod in both and glue them together.
But I can't remove the main rod (orange circle). I sure don't want to mess the rest speedometer)which is working fine.
Any ideas on how to get this fixed?
I figure that even if I find a new gear, I don't know how I'll remove the old one and put in the new one...

[Topcat]

My speedo had a broken worm gear. Hayward Speedometer repair found one and was able to fix it.
Apparently, it's a common problem on these Rallye instruments. Std. guage doesn't have them inside. 

This is going to be one of those things where you're going to have to do some investigation by calling around for leads.

I would try here first and send it out for repair. Good luck.

http://mrheaterbox.com/instrument_clusters.htm

[351c4v71]

Just called them.
175$ to do the job !! :-(
I wish I could do this myself... Anyone here ever openned up their speedometer for this kind of repair ?
It's just a plastic gear after all...